<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style type="text/css">
div{width:200px;height:300px;display:none;background:#ddd;}
.divOn{display:block;}	

.buttonOn{background:blue;}


	</style>
	 	

 	

<script>

  for (var i=0; i<3; i++)

  {

     for (var i=2; i<5; i++)

     {

          alert(i);

      }

  }

</script>
</head>
<body>
	<button class="buttonOn">A</button>
	<button>B</button>
	<button>C</button>
	<div class="divOn">a</div>
	<div>b</div>
	<div>c</div>
	<input type="button" value="增加" id="add">
	<input type="button" value="隐藏" id="hidden"><br />
	<img src="moren.gif" />
</body>
</html>
